Dauntless is Monster Hunter type game, made by devs who are fans of MH and wanted to bring that to the PC, unfortunately for Dauntless CapCom announced that Monster Hunter World will be released on PC, but its release date is still vague and months away.
What is a Monster Hunter type ? A type of game where you pick a monster and travel to the monsters region, and try kill it and collect items to upgrade and craft, kill monsters to upgrade to kill stronger monsters.
Why is that fun ? Each monster is a unique challenge, and the action is fast paced and requires skill, no tab targeting or tank and spank while healers spam heal spells. This game is about getting in the monsters face and beating them down, avoiding the variety of deadly attacks and timing the openings to get the most hurt on the monster as possible, it is very fluid type of combat and generally doesn't waste much time between you arriving and fighting.
Dauntless will be a F2P game, with no gameplay elements up for sale, only cosmetics which are quiet abundant, the combat stuff you need to earn in game by ... you guessed it, slaying monsters.
Dauntless is currently in Closed Beta, the only way in to get lucky and obtain a key, or buy a founders pack.
Why would I want to play Dauntless ?
Slaying monsters is great fun, and with currently 5 weapons in the game each with there own style of play, you should be able to find a suitable weapon to beat down on monsters.
You can play with friends, co-op and team up to hunt your target, it gets chaotic and frantic as the monster reacts more unpredictably as there are more slayers beating on it, you can help each other with various items you can bring with to the hunt, its generally fun... you can also queue up with randoms, or just solo (though that is hard to kill off later tier monsters due to the timer).
Progression is fairly simple but it will take you some time to get far in the game.
The game uses the Unreal Engine, so its fairly accessible, and looks decent.
Game is also easy to learn control wise, and is currently best played on K+M, as controller support is still unreliable.
The game is in development by a active development team that are fans of the genre, so updates can bring interesting and exciting changes.
Dauntless can scratch that itch while you wait for Monster Hunter World, or let you experience that genre of game and find out if its for you.
Why would I not play Dauntless ?
Monster Hunter World is coming to PC in a few months, so that may kill off Dauntless.
Dauntless is in development, so that also brings in bugs and balance issues though currently the core game is smooth and rarely bugs out.
The game is very grind intensive, and the game flow can be tedious, basically periods of inactivity while you harvest and search for the target then frantic action then back to harvest and searching when the target flees to a new location.
The gear is linear and the stats are rather boring, the fun stats come from 'cells' you put in the gear but you wont feel you are gaining significant power fast.
Character customisation is limited, most of the current players have a rather similar look, even if you use dyes.
Failure is frustrating, and while you will keep the stuff you harvested on defeat, the stuff you really need is only earned when you successfully slay the monster... but it is a great feeling when you finally down the bugger

Edit: I added a Youtube video of me soloing a monster called a Gnasher, one step above the rookie Rogue Gnasher type and my current level, just to give you an idea how the typical hunt goes.
https://youtu.be/q2YD4QA5RGQ
My own thoughts : I am having fun, but there is frustration at times and I do find the slow pace of earning new looking gear to be an issue, but still those fights are fun, even going back to easier monsters, the fight is the core of the game and its pretty solid. I think if you have a few friends the game will be a blast to play together and luckily there are no real ways grieve (other than refusing to fight that is).